Field
Implementations described herein generally relate to semiconductor manufacturing and more particularly to a method and apparatus for protecting heaters from corrosion during high temperature processing.
Description of the Related Art
During the manufacture of semiconductor devices, a substrate may undergo many operations in a variety of processing chambers for the purpose of forming material layers and features suitable for an end use. For example, the substrate may undergo several depositions, annealing, and etching operations, among other operations. Device miniaturization has made small dimensions for device patterns formed in a film layer of the substrate more critical. Achieving the critical dimensions in the substrate starts with a film layer of good quality and having good adhesion to underlying film layers in the substrate.
Complete disassociation of the process gasses when forming plasma enhances the quality of films deposited on the substrate. Using high temperatures in excess of about 400 degrees Celsius provides more complete disassociation of the process gasses and also provides strong adhesion of the high quality film on the substrate. However, the high temperatures also increases the amount of material intended to be deposited the substrate to form on chamber components. Such stray depositions on chamber components (i.e., film) undesirably contribute to process contamination and process skew. Thus, to prevent process contamination and process skew, the high temperature process chamber may require periodic cleaning.
In-situ cleaning of the high temperature process chamber may be performed using cleaning agents to remove the film on the chamber components. During cleaning, the film is typically reacted into a gaseous state that, along with the cleaning agent, is pumped out the processing chamber. During the cleaning, or an etching process, using nitrogen fluoride (NF3) under high temperature, aluminum (Al) chamber components react with NF3 to form aluminum fluoride (AlFx) resulting in an AlFx powder forming in the chamber from the corrosion of Al chamber components. This extends to other corrosive plasma based chemistry, such as chlorine (Cl).
Therefore, there is a need for an improved apparatus and method of protecting high temperature chamber components from corrosion.